The ever-increasing use of electronic and digital systems in the transport sector has caused an increase in the extension and complexity of electrical installations, which are usually made up of power supply and communication cables clustered into bundles. In the aeronautics industry, this trend is more prominent: very long electric bundles made up of a high number of cables are installed in last-generation airplanes.
To form a bundle the cables must be clustered together and tied in a secure manner to form compact and wear-resistant bundle. These tying operations are usually performed by hand despite there being so many of them, affecting manufacturing times. The need to automate these operations as much as possible is therefore raised.
Several knot-tying machines are known, such as the one disclosed in US patent document U.S. Pat. No. 6,648,378 B1, showing an automatic device for tying knots on a part, such as a bundle of cables, for example. In one embodiment of said device, a complex mechanism made up of a series of rings and hooks allows arranging a filament around the part and forming a knot by transversely pulling on the filament.
Although this invention allows a simple and versatile operation by means of a pistol-like portable device, in practice the mechanism forming it limits both the type of knot and the diameter of the bundle that can be tied together by the knot.
Patent document U.S. Pat. No. 8,573,656 B1 discloses another machine that allows making knots automatically formed by a multi-actuator imitating the movement of a human hand making a knot by means of a coordinated sequence of actions.
One of the biggest drawbacks of this device is the complicated pneumatic installation which it requires and which limits its application in stationary processes.